From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx141.postini.com [74.125.245.141]) by kanga.kvack.org (Postfix) with SMTP id 0040D6B0005 for ; Thu, 4 Apr 2013 22:22:53 -0400 (EDT) MIME-Version: 1.0 Message-ID: <7058b4bf-4473-4755-a017-e32f5389a73f@default> Date: Thu, 4 Apr 2013 19:22:21 -0700 (PDT) From: Dan Magenheimer Subject: RE: [PATCHv8 5/8] mm: break up swap_writepage() for frontswap backends References: <1365113446-25647-1-git-send-email-sjenning@linux.vnet.ibm.com> <1365113446-25647-6-git-send-email-sjenning@linux.vnet.ibm.com> <515DFF08.3060005@linux.vnet.ibm.com> In-Reply-To: <515DFF08.3060005@linux.vnet.ibm.com> Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: quoted-printable Sender: owner-linux-mm@kvack.org List-ID: To: Seth Jennings , Andrew Morton Cc: Greg Kroah-Hartman , Nitin Gupta , Minchan Kim , Konrad Wilk , Robert Jennings , Jenifer Hopper , Mel Gorman , Johannes Weiner , Rik van Riel , Larry Woodman , Benjamin Herrenschmidt , Dave Hansen , Joe Perches , Joonsoo Kim , Cody P Schafer , Hugh Dickens , Paul Mackerras , linux-mm@kvack.org, linux-kernel@vger.kernel.org, devel@driverdev.osuosl.org, Bob Liu > From: Seth Jennings [mailto:sjenning@linux.vnet.ibm.com] > Subject: Re: [PATCHv8 5/8] mm: break up swap_writepage() for frontswap ba= ckends >=20 > On 04/04/2013 05:10 PM, Seth Jennings wrote: > > swap_writepage() is currently where frontswap hooks into the swap > > write path to capture pages with the frontswap_store() function. > > However, if a frontswap backend wants to "resume" the writeback of > > a page to the swap device, it can't call swap_writepage() as > > the page will simply reenter the backend. > > > > This patch separates swap_writepage() into a top and bottom half, the > > bottom half named __swap_writepage() to allow a frontswap backend, > > like zswap, to resume writeback beyond the frontswap_store() hook. > > > > __add_to_swap_cache() is also made non-static so that the page for > > which writeback is to be resumed can be added to the swap cache. > > > > Acked-by: Minchan Kim > > Signed-off-by: Seth Jennings >=20 > Adding Cc Bob Liu. >=20 > I just remembered that Bob had done a repost of the 5 and 6 patches, > outside the zswap thread, with a small change to avoid a checkpatch > warning. I didn't pull that change into my version, but I should have. >=20 > It doesn't make a functional difference, so this patch can still go > forward and the checkpatch warning can be cleaned up in a subsequent > patch. If another revision of the patchset is needed for other > reasons, I'll pull this change into the next version. >=20 > I think Dan and Bob would be ok with their tags being applied to 5 and 6: >=20 > Acked-by: Bob Liu > Reviewed-by: Dan Magenheimer >=20 > That ok? OK with me. I do support these two MM patches as candidates for the 3.10 window since both zswap AND in-tree zcache depend on them, but the silence from Andrew was a bit deafening. Seth, perhaps you could add a #ifdef CONFIG_ZSWAP_WRITEBACK to the zswap code and Kconfig (as zcache has done) and then these two patches in your patchset can be reviewed separately? -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org